OXYGEN REQUIREMENTS OF BREWING STRAINS OFSACCHAROMYCES UVARUM (CARLSBERGENSIS)-BOTTOM FERMENTATION YEAST

Abstract
The requirement of oxygen by brewing strains of Saccharomyces uvarum (carlsbergensis) varies with the strain. For a given strain, the requirement can be assessed quantitatively from an equation developed on the basis of model fermentations carried out at four different oxygen levels under a set of standardized experimental conditions. Using this equation, the strains are subdivided into four groups, differing significantly in their oxygen requirements. Among several other factors, access to oxygen during propagation of pitching yeast determines the magnitude of the oxygen requirement during subsequent fermentation. In this regard, the strains referred to the groups having a high demand for oxygen are the most sensitive.